Breathing apparatus



Aug. 16, 1966 K. G. WILLIAMS 3,

BREATHING APPARATUS Filed May 17, 1963 4 Sheets-Sheet l K. G- WILLIAMSBREATHING APPARATUS Aug. 16, 1966 4 Sheets-Sheet 2 Filed May 1'7, 1963EMIWI Aug. 16, 1966 K. G. WILLIAMS BREATHING APPARATUS Filed May '17,1963 4 Sheets-Sheet 3 FIGS Aug. 16, 1966 K. G. WILLIAMS BREATHINGAPPARATUS 4 Sheets-Sheet 4 Filed May 17, 1963 3,266,489 Ce PatentedAugust 16, 1966 3,266,489 BREATHING APPARATUS Kenneth Gabriel Williams,Surrey, England, assignor to Vickers Research Limited, London, England,a British company Filed May 17, 1963, Ser. No. 281,290

' 1 Claim. (Cl. 128-142) This invention relates to a closed circuitbreathing apparatus. I

According to the present invention there is provided a closed circuitbreathing apparatus comprising means for attachment to the users facefor communicating with the breathing passages of the breathingapparatus, such as a mouthpiece or face mask, a bag for containing thegaseous medium to be breathed, a first conduit for conveying gaseousmedium from the bag to the mouth-piece or face mask through a firstnon-return valve permitting flow in the direction from the bag to themouth-piece or face mask, a second conduit for conveying gaseous mediumfrom the mouth-piece or face mask to the bag through a second non-returnvalve permitting flow in the direction from the mouth-piece or face maskto the bag, wherein the bag is incorporated in a garment to be worn bythe user of the apparatus, the bag being arranged for bearing on thechest of the user of the apparatus.

For a better understanding of the present invention and to show how thesame may be carried into effect reference will now be made, by way ofexample, to the accompanying drawings, in which:

FIGURE 1 is a back view of a fireman wearing a jacket having a closedcircuit breathing apparatus incorporated therein, the jacket being shownin a portion cut-away to reveal parts of the breathing apparatus,

FIGURE 2 is a front view of the jacket when opened out,

FIGURE 3 is, to an enlarged scale, an elevational view, partly insection, of the breathing apparatus with the jacket removed,

FIGURE 4 is, to an enlarged scale, an end view of part of the apparatusof FIGURE 3, and also showing a pressure gauge, and

FIGURE 5 is, to an enlarged scale, a part-section on the line VV ofFIGURE 3.

The breathing apparatus is carried by a jacket 2 having a compartment 1on the back thereof. Within the compartment 1 are an oxygen bottle 3, areducing valve 4 connected to the outlet of the bottle, a container 5for air cooling and purifying elements, and a box 12 containing radioand other electronic equipment. This electronic equipment forms no partof the present invention and will therefore not be described further. Agastight inflatable bag 6 is incorporated in the jacket 2 so that in usethe bag 6 extends over the chest and the upper part of the back of thewearer. A flexible air supply pipe 7 leads from one end of the container5 to a mouth-piece 8 and a flexible air return pipe 9 leads from themouth-piece 8 to the other end of the container 5. Straps 10, 11 and 12Ahold the oxygen bottle 3, the container 5 and the box 12 in thecompartment 1. The pipes 7 and 9 are led through holes in the upper wallof the compartment 1 and under the shoulder loops 13 of the jacket 2.Most of the weight of the components in the compartment 1 is carried byshoulder straps 14 which are attached to the part of the jacket 2forming the wall 1A of the compartment 1. The straps 14 pass throughupper and lower slits 15A in the lining 15 of the jacket 2. A belt 16 isalso secured to the wall 1A of the compartment 1, the belt 16 beingpassed through the lower slits 15A and provided with a buckle 16A andfastener 16B for enabling the belt when passed around the waist of thewearer to be secured at the front of the jacket 2. The bag 6 is disposedbetween the lining 15 and the jacket 2 and is attached to the lining 15by means of press studs (not shown).

The oxygen bottle 3 has an on-off valve 17 (FIGURE 3) at its outlet, thecontrol of this valve being by means of a knob 18. The reducing valve 4is fitted to the bottle outlet on the downstream side of the valve 17and a flexible pipe 19 connects an outlet 4A of the reducing valve 4 toan inlet tube 20 of the container 5. A flexible pipe 21 (FIGURE 4)connects the valve 4 to a pressure gauge 22 which is carried on a frontupper part of the jacket 2 where the gauge 22 is visible to the wearer.The gauge 22 serves to give an indication to the wearer of the amount ofoxygen remaining in the bottle 3. A so-called Bowden cable 23 leads fromthe valve 4 to a control lever (not shown) manually operable by thewearer to cause oxygen from the bottle 3 to by-pass the reducing valve 4and flow from the valve 17 directly to the flexible pipe 19.

A box 24 is housed in the right-hand part (FIGURE 3) of the container 5,the vertical walls of the box 24 being imperforate except for arectangular aperture 25 in the middle of the right-hand end wall 26(FIGURE 3). The top and bottom walls 27 and 28 of the box 24 are of wiremesh, as are two intermediate walls 29 and 30 which form the top andbottom walls of the channel 31 of rectangular cross-section extendingfrom the aperture 25 to the left-hand wall 26A of the box 24. The sidewalls of the channel 31 are constituted by walls of the box 24. Sodalime for absorbing carbon dioxide is contained in the chambers formedbetween the walls 27 and 29, 28 and 30. Two further channels 32, 33 aredefined by the walls 27 and 28 and the top and bottom walls of thecontainer 5. An outwardly protruding flange 34 extends around theperimeter of the aperture 25 and is inserted through a correspondinglysized aperture in the adjacent end wall of the container 5 to penetrateanother rectangular aperture in the side wall of a narrow box 35. Asealing ring 36 surrounds the part of the flange 34 that is between thecontainer 5 and the box 35, and a screw-threaded projection 37 ismounted on a bridge between opposite sides of the flange 34 to penetratea hole in the wall 35A of the box 35 remote from the container 5. Ascrew cap 38 on the projection 37 secures the box 24 inside thecontainer 5 and the narrow box 35 to the adjacent end of the container5. A relief valve assembly 39 is provided on the wall 35A of the box 35for permitting controlled escape to atmosphere. The relief valveassembly 39 is adjusted so that it allows escape of gas from the box 35when the pressure therein is slightly above atmospheric, say, two inchesof water above atmospheric.

A finned cooling unit 40 is housed in the left-hand part of thecontainer 5 (FIGURE 3). Ice is packed and sealed inside the unit 40prior to use, and the fins allow gaseous medium in the container 5 tocirculate past the unit 40 to be cooled thereby. A cover 41 hermeticallyseals the adjacent end of the container 5. The cover 41 is removable topermit replacement of the unit 40 by a fresh one.

The bag 6 is provided with an insert 42 (FIGURE 5) in the form of ahollow cylinder projecting from the bag 6. The insert 42 is closed atits end 42A that is remote from the bag '6 and has two axially extendingapertures 42B. The insert 42 is introduced through a hole in the Wall ofthe container 5 that is normally adjacent the users back and its closedend abuts the opposite wall of the container 5. A flange 43 around thebase of the insert 42 contains a sealing ring 44 and a screw capassembly 45 sealingly connects the insert 42 and bag 6 to the container5. A hole 46 places the inside of the bag 6 or in communication with theinterior of the container via the axially extending apertures 42B of theinsert 42.

The flexible supply pipe 7 for the mouth-piece 8 leads from theleft-hand end (FIGURE 3) of the top wall of the container 5 to one endof a rigid tube 47. Two non-return valves are housed in the tube 47, oneacting as an inlet valve, the other as an outlet valve, for themouth-piece 8. The inlet valve is shown in FIGURE 3 I and consists of aflap 48 of impermeable resiliently flexible material such as that soldunder the trade name Melinex, secured at one point to the angled end ofa sleeve 49 which fits snugly in the left-hand end part of the tube 47.The closed position of the flap 48 is shown in full lines in FIGURE 3and the open position in chaindotted lines. The outlet valve (not shown)is of similar construction to the inlet valve and is housed in therighthand end part of the tube 47, the flap (not shown) of the outletvalve being disposed on the right-hand side (FIG- URE 3) of theassociated angled sleeve (not shown). The return pipe 9 leads from thetube 47 to the narrow box 35. The mouth-piece 8 is secured over anaperture in the tube 47 between the inlet and outlet valves and isprovided with extensions 50 for attachment to a headharness (not shown).

The operation of the breathing apparatus, starting from the moment theuser of the apparatus begins to inhale, is as follows. At this momentthe bag 6 is filled with oxygen, and a steady supply of oxygen isflowing from the bottle 3 into the container 5. The valve 4 permits flowof oxygen from the bottle 3 to the pipe 19 at a rate of 2 to 4 litres aminute at normal temperature and pressure. As the user breathes in theflap 48 of the inlet valve is opened and oxygen is drawn from the bag 6,through the insert 42, past the cooling unit 40 and along the supplypipe 7. The unit 40 serves not only to cool the oxygen supplied to themouth-piece 8 but also condenses water vapor that may be contained inoxygen. The unit 40 thus both cools and dries the oxygen fed to themouth-piece 8. Oxygen issuing from the inlet tube 20 is also drawn upthe pipe 7. The outlet valve in the tube 47 is maintained in its closedposition by this inhalation. When the bag 6 is filled with oxygen itexerts a pressure on the users chest and on the upper part of his back.As oxygen is drawn from the bag 6, the latter deflates thus facilitatingchest expansion. Furthermore the chest expansion by squeezing the bag 6assists in the circulation of gas through the apparatus. The supply ofoxygen from the bottle 3 serves only to replace losses incurred and isnot sufficient to keep the bag 6 inflated during inhalation.

When the user starts to breathe out the exhaled gases are directed bythe non-return valves in the tube 47 along the return pipe 9 into thenarrow box 35 and through the aperture 25 into the channel 31, watervapour in the gases condensing in the box 35. From the channel 31 thegases permeate through the mesh walls 29 and 30 and the soda lime in thechambers of the box v24 where carbon dioxide is absorbed, to emergethrough the mesh walls 27 and 28 into the channels 32 and 33. The gasesfrom which carbon 4 dioxide has been extracted then pass to the bag 6via the insert 42, the inflation. of the bag 6 being aided by the supplyof oxygen from the bottle 3. The pressure on the users back and chestexerted by the inflating bag 6 as he breathes out assists the userslungs in exhaling.

As gaseous medium in use of the apparatus is circulated back and forthbetween the bag 6 and the mouth-piece 8 it will be understood that thebreathing apparatus is a socalled closed circuit one.

The capacity of the bag 6 is such that a user of the apparatus cannotexhause it in one breath.

It will be understood that, instead of the mouth-piece 8, a face maskmay be used.

I claim:

In a closed circuit breathing apparatus, including a garment havingfront and back portions -for supporting elements of the apparatus andarranged to be Worn by the user, a gas-tight inflatable and deflatablebag for containing gaseous medium to be breathed by the user, said bagbeing incorporated in said garment, means for conducting a breathing gasto the breathing bag, an attachment means for mounting on the face ofthe user, a first conduit including a one-way inlet valve for conductinggaseous medium from the bag to the face attachment means, a gaspurification chamber carried on the garment, and a second one wayconduit for conducting exhaled gases from the face attachment means tothe gas purification chamber and for conducting purified gases therefromto the breather bag, the improvement in which the breather bag extendshorizontally around the users body when in use, and has oppositelymounted portions incorporated respectively in the front and back of thegarment in positions respectively bearing only on the chest and back ofthe user of the apparatus, said garment including means for retainingand holding said portions of the breather bag to the chest and back ofthe user, said breather bag being inflatable and deflatable respectivelyin timed relation to the contraction and expansion of the chest of theuser while breathing, the breathing of the user or the apparatus beingfacilitated by the inflation and deflation of the bag in cooperationwith said retaining and holding means whereby chest expansion and.contraction together with the circulation of the gaseous breathingmedium through the apparatus is facilitated.

References Cited by the Examiner UNITED STATES PATENTS- 996,135 4/1910Poe l2819l 2,402,984 7/1946 Browne 128-142 FOREIGN PATENTS 733,4737/1955 Great Britain.

RICHARD A. GAUDET, Primary Examiner.

D. S. BURKS, W. E. KAMM, Assistant Examiners.

